Skip to main content

LeetCode Two Sum

Sep 13, 2023C S
Loading...

More JavaScript Posts

copyString.js

Nov 8, 2023LeifMessinger

0 likes • 6 views

function copyString(text){
async function navigatorClipboardCopy(text){
if(document.location.protocol != "https:"){
return false;
}
return new Promise((resolve, reject)=>{
navigator.clipboard.writeText(text).then(()=>{resolve(true);}, ()=>{resolve(false);});
});
}
function domCopy(text){
if(!(document.execCommand)){
console.warn("They finally deprecated document.execCommand!");
}
const input = document.createElement('textarea');
input.value = text;
document.body.appendChild(input);
input.select();
const success = document.execCommand('copy');
document.body.removeChild(input);
return success;
}
function promptCopy(){
prompt("Copy failed. Might have ... somewhere. Check console.", text);
console.log(text);
}
function done(){
alert("Copied to clipboard");
}
navigatorClipboardCopy(text).catch(()=>{return false;}).then((success)=>{
if(success){
done();
}else{
if(domCopy(text)){
done();
}else{
promptCopy();
}
}
});
}

Rings and Rods

Nov 19, 2022CodeCatch

0 likes • 1 view

// There are n rings and each ring is either red, green, or blue. The rings are distributed across ten rods labeled from 0 to 9.
// You are given a string rings of length 2n that describes the n rings that are placed onto the rods. Every two characters in rings forms a color-position pair that is used to describe each ring where:
// The first character of the ith pair denotes the ith ring's color ('R', 'G', 'B').
// The second character of the ith pair denotes the rod that the ith ring is placed on ('0' to '9').
// For example, "R3G2B1" describes n == 3 rings: a red ring placed onto the rod labeled 3, a green ring placed onto the rod labeled 2, and a blue ring placed onto the rod labeled 1.
// Return the number of rods that have all three colors of rings on them.
let rings = "B0B6G0R6R0R6G9";
var countPoints = function(rings) {
let sum = 0;
// Always 10 Rods
for (let i = 0; i < 10; i++) {
if (rings.includes(`B${i}`) && rings.includes(`G${i}`) && rings.includes(`R${i}`)) {
sum+=1;
}
}
return sum;
};
console.log(countPoints(rings));

Reverse a string in Java

Nov 20, 2022Helper

0 likes • 1 view

new StringBuilder(hi).reverse().toString()

native data structures

Nov 19, 2022CodeCatch

0 likes • 0 views

const nums = [1, 2, 3];
const strs = Array.from('est');
nums.push(6);
nums.push(4, 9);
strs.unshift('t');
nums.length; // 6
nums[nums.length - 1]; // 9
strs[0]; // 't'
strs[2]; // 's'
nums.slice(1, 3); // [2, 3]
nums.map(n => n * 2); // [2, 4, 6, 12, 8, 18]
nums.filter(n => n % 2 === 0); // [2, 6, 4]
nums.reduce((a, n) => a + n, 0); // 25
strs.reverse(); // ['t', 's', 'e', 't']
strs.join(''); // 'test'
const nums = new Set([1, 2, 3]);
nums.add(4);
nums.add(1);
nums.add(5);
nums.add(4);
nums.size; // 5
nums.has(4); // true
nums.delete(4);
nums.has(4); // false
[...nums]; // [1, 2, 3, 5]
nums.clear();
nums.size; // 0
const items = new Map([
[1, { name: 'John' }],
[2, { name: 'Mary' }]
]);
items.set(4, { name: 'Alan' });
items.set(2, { name: 'Jeff' });
items.size; // 3
items.has(4); // true
items.get(2); // { name: 'Jeff' }
items.delete(2);
items.size; // 2
[...items.keys()]; // [1, 4]
[...items.values()]; // [{ name: 'John' }, { name: 'Alan' }]
items.clear();
items.size; // 0

React Short Circuit Evaluation

Feb 3, 2021C S

0 likes • 0 views

import React, { useState } from 'react' import Welcome from '../components/Welcome' function About() { const [showWelcome, setShowWelcome] = useState(false) return ( <div> {showWelcome ? <Welcome /> : null} </div> <div> {showWelcome && <Welcome /> } </div> ) } export default App

arithmetic progression

Nov 19, 2022CodeCatch

0 likes • 0 views

const arithmeticProgression = (n, lim) =>
Array.from({ length: Math.ceil(lim / n) }, (_, i) => (i + 1) * n );
arithmeticProgression(5, 25); // [5, 10, 15, 20, 25]